Telephone-exchange system.



W. A. WYNNE.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION IILED MAB. 9, 1909. 944,120, Patented Dec. 21, 1909.

2 SHEETS-SHEET 1.

W. A. WYNNE.-

- TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAR. 9, 1909. 944, 1 20. Patented Dec. 21, 1909.

2 SHEETS-SHEET 2.

hurrah srarias PATENT curios.

WILLIAM ANDREW WYNNE, SF RALEIGH, NORTH CAROLINA.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Xatent. Patgnted Dec, 21, 1999,, Application filed March 9, 1909. Serial No. 482,329.

To all whom it may concern:

Be it known that I, WiLLIAM ANDREW \Vrrmn, a citizen of the United States, residing at Raleigh, in the county of \Vakc and State of North Carolina, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention ;relates to telephone exchange systems and has for its object the provision oi? means whereby calling subscribers may be promptly answered without the delay usually attendant upon an operators plugging into an answering jack. .zflhe present invention constitutes an improvement on that for which I have been rante-d Letters Patent of the United States, R 0. 911,798, dated February 9, 1909. in that case I showed and claimed a special relay for each line, adapted to become energized when the subscriber is calling, to U011-- meet his line directly to the operators talking circuit. In the present case I have modifled the circuit so that a single relay will serve for a number of lines. This relay may be connected in various ways, but the arrangement I now consider the best places it in parallel with some portion of the pilot circuits, which are common to'a group of lines.

The invention is illustrated in the accompanying drawings wherein Figure l is a diagram showing;' two subscribe-rs lines, a cord circuit, an opera ofs telephone set, and my special calling relay arranged in parallel with the pilot lamp. Fig. 2 is a diagram of a modified arrange ment in which the special relay is in parallel with the night alarm.

Referring to the drawings, A and A. are two subscribers stations, connected to a central ofiicc by line wires l--2, il-4 respec tively. As the connections and arrangement of both lines are the same, a detailed dcscripl'ion of the line 1 2 will answer for both. The wires 1 and 2 terminate .at the central oliice on contact springs (shown for convenience as armatures) 5 and (3 of the cut-ofl relay 7, which are normally closed on contact points 8 and 9, connected e spectively to around and to the line relay 10, from which the wire 11 passes to the main battery B. The line relay 10 through its armature 12 controls a local circuit 13 passing to the line lamp 141- and thence to the pilot relay 15 which is common to a group of lines, as indicated by the stub wires 16, which go to the lamps 14 of other lines. The circuit of the relay 15 is completed by wire 17 to ground, and armature 12 is connected co-battery through the wire 11.

The relay 15, through its grounded spring contact 18 (shown for convenience as an armature), controls the local circuit 19 of the pilot lamp 20, this circuit being completed by wire 21, which passes to the night alarm relay 22, common to a. group of lines as indicated by the stub wires extending therefrom. This relay 22 is connected by wire 23 to the main battery 13, and through its armature 24;, also connected to battery through wire 23, it controls the local circuit 25 of the night alarm 26, which may be common to all the lines in the exchange or to an desired grou p thereof.

itlxte'nding from the wire 19 is a branch wire 27, which passes to the special listening relay 28, and thence by wire 2-9 to battery, this being in parallel. with the pilot lamp connections 19, 20, 21, 2-2 and and being closed for the passage of battery current whenever the pilot relay lti-is encr ized.

'lhc operators set is shown at hand is connected in parallel to contacts'in the listening keys 30 of all the cord circuits at the position to which this telephone set is appropriated, and of which the single cord circuit shown is a symbol. The operators set is also connected across a pair of wires 1-32, which pass to contacts in the relay :28. One cooperating contact 33.01 this relay (shown for convenience as an armature) is grounded through wire 34; and the other corresponding contact (also shown as an armature) forms the terminal of a wire lead 36 having a plurality of branches 36, 3G", 3G", 36, etc, each of which contains a condenser 37, and is connected to contact 9 of a particular line. These branches are for the passage of talking currents only, and each of them is individual to its own line, all. of them. however, being in parallel when their. line :ircu ils are simultaneously closed.

The operation of this circuit is as follows Assuming the subscriber A to be calling, his receiver is removed from the hook, and batlcry current llows thiough the following path: B, 23. 11, 10,9, (3. 2, substation, 1,5, 8, ground to battery. Relay ll) pulls up, clos lug the following circuit: B, 13, 11, 1i, 3, ll, l6, l5, l7, ground to batter Lamp 14 li hts and relay l5 ulls u i closin the fol- 7 lowing puot signal circuit: B, 23, 2:2, :21, 2o, 19 1S 1?. "round to batter lilot lam) 20 7 a n 1 lights, and f the night alarm 2b is in service, the following circuit is closed ii, 23, 24-, 25, 26, ground to battery. The pulling upof armature l8 also closes the following circuit: B 23 29 28 27 to if. ground to batterv. a a a i 7 a i r w .1 lhe special listemng relay :3 thereupon pulls up and the line 1 2 at once connected to the operalofs telephone set by the iollowing path ground, ii-l, 3:2, 31, U, 32,

35, 36, 3O, 37, 2),, l". Tl. substation, 1, 5, 8, ground. The subscrilmr can speak to the operator as soon as he puts his receiver to his ear, and where a single line is calling, the signals ll and 2t) are therefore superfluous, except a: they enable the operator to identify the line for connective purposes without the subscriber stating his number. On the other hand, it several lines are calling'sin'uiltancously, and all the subscribers speak at once, confusion is avoided by the operator immediately inserting answering plugs in all the jacks except one, or if she pleases in all of them. The subscribers instructions are then taken separately by means of the listening. keys 30 in the ordinary way. I have found in practice, however, that this condition is rare, and that it is very rare for more than two calls to come in simultaneously. An operator can handle two calls at once Without resorting to the listening keys, especially as the line lamps 14 designate the two lines calling, and it she has'had any experience at that position on the board, she is probably able to difierentiate between the voices, and surely so by the subscribers giving their numbers, as for example, 357 on T26. It will be observed that this is similar to the method of procedure in the old and well-known Law system, of which this is in fact a modernized and highly improved species.

Referring now to Fig. 2, l have shown therein only the terminals of the line l2, which are connected as before, and the sereral relays and jacks belonging to the line.

In this modification the special relay 28 is connected by it's Wire 27 to the wire 25 of the night; alarnr 26, becoming energized when the rclay-QQ pulls up. It will be-obscrvedjthatnin both figures I have shown-a switch 26 fforcutting ofi the night alarm,

but 'tliisldoes' not afi'ect the relay 28 which is in a para lel' br-anch,'and will therefore al- Ways resp'ondwhcn the night alarm relay is energized. The other connections, and the operationof the circuits in this figure are the same as those of Fig. l.

' ltshould behotcd that when the cut-oft relay 7 pulls up, it connects lhc line to its jail; or jacks (multiple jacks being shown for each line), and when the operator gets the number she connects the l nes by plug- 1' am aware that it has heretofore been.

proposed to use a switch or other piece of apparatus in connection with a common operators telephone circuit, to connectthe lattcr with any one group of lines when calling, and I therefore do not claim this idea broadly.

The essential feature of my invention is the special relay controlling parallel branches from a plurality of lines to a common cperatons circuit, and adapted to connect all of them thereto when any one of them is calling.

In the following claims, where I refer to special service or the special relay, it

should be understood that this language may refer to the ordinary pilot relay shown at 1:3 in my drawings, which may obviously jack or one to the jack of be fitted with additional contact springs, so

as to perform the functions of the extra relay Q8, and save that relay. This or other substitutions are clearly Within the working scope of any well informed electrician or telephone engineer, and may be regarded as involving merely the use of equivalents.

Having thus described my invention what 1 claim and desire to secure by Letters Patcut is:

l. in a telephone exchange system, a plurality of subscribers lines extending to a central oflice, with means therein to interconnect the lines, an operators telephone circuit, an individual signal for each line, and a relay common tosaul lines acting when any line comes into use to connect" them all directly with the operators circuit.

2. in a telephone exchange system, a plurality of subscribers lines extending to a central ollice, plug and cord circuits for interconnecting the lines, a listening and ringing key and operators circuit connections to each cord, an individual signal relay. for

each line, a common relay for all the lines adapted to be energized when any, line is calling to connect them all to the operators circuit, and a cut-off i'elay acting when a cord is connected with a line to disable the line signal amldiscounect the special relay therefrom.

3. in a telephone, exchange system a plurality of lines, a line relay fol-each line, a group of pilot signal means torall the lines,

and a special relay with its windings in parallel with said pilot means, and with connections from ItS contacts on one side to all the lines in parallel and on the other to an opera'tors telephone circuit.

4. In a telephone exchan e system, a plurality oflines, a central 0 ice terminal for each line, and operators link circuits for interconnecting said terminals, a listening key for each line circuit, an operators telephone connected in parallel to all the listening, keys, a line relay and signal for each line, a common relay having its windin s connected so as to be controlled by a ilurality of said line relays, and having its contacts connected on one side in parallel to all of the lines by whichit is thus controlled, and on the other side to the operators tele 'ihone, whereby when any line ill the group is calling, al the lines in that group will be simultaneously connected to die operator for immediate service.

In a telephone exchange systen'i, a plurality of subscribers lines, having line relays and terminal jacks at a central otficc, o )erators cord circuits for interconnecting tl ie several jacks, listening keys for the cord circuits, an operators telephone connected in parallel to the listening keys and a specia service outfit comprising a listening relay common to and controlled by a plurality or the line relays, and having its contacts connected on one .sidethrough parallel branches containing condensers, to all of the lines by which it is controlled, and on the other side to the operators telephone, whereby when any line in the special service group is calling, all the lines of that group will be connected to the o'perators telephone without the insertion of a plu lntcstiniony whereof I atlix my signature in presence of two witnesses.

WILLIAM ANDREW WYNNE. Witnesses:

'lnoiuas DUuAN'r, llowaun l CLEMENT. 

